In 2006, the Army forced Hennis, who was retired, back into active duty to face charges in a 1985 triple slaying. According to the Army, new DNA evidence was found by civilian investigators linking Hennis to the stabbing deaths of Kathryn Eastburn and her two daughters - 5-year-old Kara Sue and 3-year-old Erin Nicole.
Prosecutor Capt. Matthew Scott said in his closing that DNA found in sperm left in the body of Kathryn Eastburn matches Hennis.
"The person that slaughtered her, raped her -- the person that raped her left his sperm," Scott said.
Hennis's lawyer Frank Spinner hinted in closing arguments that the sperm could have been left by Hennis if he and Eastburn had consensual sex days earlier - a suggestion that Eastburn's family in the courtroom clearly found offensive.
"Does the evidence take you beyond adultery to murder?" Spinner asked the 14-member panel deciding Hennis' fate. "You should follow that evidence where ever it leads you, no matter how uncomfortable it may make you."
Scott dismissed the consensual sex scenario - or that the DNA sample could have been contaminated - as fantasy.
Defense lawyers have also focused their efforts on attacking the credibility of eyewitnesses, including testimony from Patrick Cone who testified he saw Hennis in the driveway of the Eastburn home at about 3:30 a.m. on the night of the murders. Defense lawyers presented witnesses who testified that Cone expressed doubt over his identification of Hennis.
Other defense experts focused on the lack of physical evidence linking Hennis to the murders. An expert in forensic pathology said the killer would have been covered in blood. But investigators did not find blood in Hennis' car or home.
A crime scene specialist testified that no physical evidence -- fiber, hair or blood -- was found at the scene or in Hennis' car or home that links him to the crime. His fingerprints were also not found at the crime scene.
A civilian jury acquitted Hennis in 1989 after the NC Supreme Court overturned his initial conviction in 1986. Hennis couldn't be tried again in civilian court, so he was charged by the military, which can pursue the case because its court system is a different jurisdiction.
Hennis, who had adopted the Eastburns' dog several days before the killings, was arrested four days after the bodies were found when Cone picked him out of a photo lineup.
Eastburn's husband, Air Force Capt. Gary Eastburn, was in Alabama at squadron officer's training school at the time of the stabbings. The Eastburns' 22-month-old daughter, Jana, was at the home but was left unharmed in her crib.
The case spawned a 1993 book entitled "Innocent Victims," which was followed by a cable television miniseries.
Hennis retired from the military in 2004 and was living in Lakewood, Washington before his latest arrest.